1. Field of the Invention
The invention relates to a mobile station comprising an integrated antenna, an antenna ground plane and an antenna raising component arranged to keep the antenna at a determined height in respect of the ground plane.
The invention further relates to an antenna arrangement for a mobile station, comprising an integrated antenna, an antenna ground plane and an antenna raising component arranged to keep the antenna at the right distance from the ground plane.
The invention relates to wireless mobile stations, such as mobile telephones, communicators and corresponding mobile stations. The invention particularly relates to mobile stations comprising an integrated antenna.
2. Brief Description of Related Developments
The progress of electronics and telecommunication technology allows the size and weight of mobile stations to be continuously decreased. Owing to this, mobile stations are increasingly handy and easy to carry along in everyday life. Integrated antennas have replaced external antennas in mobile stations, thus improving the ease of use. An integrated antenna is placed entirely inside the covers of a mobile station, thus not hampering the handling of the telephone. A protruding antenna is known to easily get stuck in clothing, for example. An integrated antenna is also well protected from external loads, impacts and the like, and does therefore not break as easily as an external antenna. Furthermore, antenna technology has developed to a degree that the properties of an integrated antenna can be made sufficiently good. Let is be pointed out that in the present application, the term mobile station refers particularly to mobile telephones and communicators or other telecommunications devices.
The basic shape of an integrated antenna is usually a thin, planar structure having wide boundary dimensions, i.e. what is known as a flat profile antenna. The advantages of such an antenna type include lightness, thinness, ease of installation, adaptability to mass production, and, as a result, low production costs. A flat profile antenna is quite simple to produce as a two-frequency antenna; the interface circuits and wirings can be produced at the same time as the antenna itself.
Between a flat profile antennaxe2x80x94hereinafter referred to as xe2x80x98antennaxe2x80x99xe2x80x94and the ground plane is an antenna raising component, which keeps the antenna in the right place and at the right height in respect of the ground plane. The raising component is usually made as spacious as possible for it to be as low-loss as possible. The higher the antenna, i.e. the more air-space between the antenna and the ground plane, the broader are the impedance band and radiation efficiency achieved. The significance of height in amplification is low at dot frequency, but owing to the broadening of the impedance band, the amplification of the antenna in the desired band increases. There is certainly often other material than air between an antenna and the ground plane, but owing to the freeness of losses and lightness of the air, as spacious a structure as possible is preferable in said application. Most frequently, the antenna is arranged in a space between the back cover and the circuit board in the mobile station, and its height is maximized according to the height of said space. Consequently, when the thickness of a mobile station is to be reduced, the height of the antenna has to be reduced, and this raises the resonance frequency of the antenna and impairs the properties of the antenna. Increasing the size of the planar part of an antenna can compensate for the lowering of the antenna, but then the width and/or length of the mobile station have to be increased, which is naturally contradictory to the intention of decreasing the external dimensions of the mobile station.
It is the object of the present invention to provide an antenna arrangement and a mobile station so as to avoid the above drawbacks.
The mobile station of the invention is characterized in that the antenna, the antenna ground plane and the antenna raising component are arranged in a space shared with a speaker of the mobile station, and that the antenna is substantially higher than the space between a back cover and a circuit board in the mobile station.
The antenna arrangement of the invention is characterized in that the antenna arrangement is arranged in a space shared with a speaker of the mobile station and that the antenna is substantially higher than the space between a back cover and a circuit board in the mobile station.
An essential idea of the invention is that the spaces used by the antenna and speaker of the mobile station are combined and that the antenna is higher than the space between the back cover and the circuit board in the mobile station. Furthermore, it is the idea of a preferred embodiment that the echoing volume of the speaker is substantially convergent with the empty space in the antenna raising component. It is the idea of a second preferred embodiment that the speaker is arranged as close as possible to the front cover of the device. It is an idea of a third preferred embodiment that an antenna circuit board is also arranged in said space. It is an idea of a fourth preferred embodiment that the antenna is a planar inverted F-antenna (PIFA). It is an idea of a fifth preferred embodiment that electronic components, whose circuitries are preferably made by the MID method (Moulded Interconnect Device), are fastened to the antenna raising component. It is the idea of a sixth preferred embodiment that an assembly module is formed from the antenna, the antenna raising component and the speaker.
It is an advantage of the invention that the height of the antenna is not limited to the height of the space between the cover and the circuit board, but substantially the entire height between the front and rear covers of the mobile station can be utilized by the height of the flat profile antenna, whereby an integrated antenna having maximal performance can be arranged within the external dimensions of the mobile station. Furthermore, the echoing volume of the speaker is as large as possible in respect of the external dimensions of the mobile station, whereby its frequency characteristics are better. An antenna circuit board allows the space to be utilized also in the placement of electronic components, which also improves the efficiency of the use of space. When the wirings and components are fastened directly to the antenna raising component, no separate circuit board is needed, and this further decreases the external dimensions and weight of the device, and simplifies the structure and manufacture of the mobile station. An assembly module speeds up the assembly of the mobile station, thus reducing production costs.